1. Field of the Invention
The present invention is directed to a method, and an arrangement for implementing the method, for dependable transmission of service data to terminal equipment from a remote location, and in particular to a method and arrangement for transmitting and storing a new postage fee table in a postage computer in a secure manner.
2. Description of the Prior Art
German PS 38 23 719 and U.S. Pat. No. 4,138,735 disclose initiating a reloading of a fee schedule table for postage fees from a remote data central at specific points in time. If the data exchange is initiated by the server of the data center, the postage meter machine must remain constantly activated, which is, of course, disadvantageous.
Alternatively, U.S. Pat. No. 5,490,077 and U.S. Pat. No. 5,606,508 disclose initiating the data loading on demand by the postage meter machine, with the data base being updated dependent on conditions (such as, for example, name, date) after the postage meter machine is turned on. In order to be able to equip a large number of postal customers with a fee schedule table in the relatively short time between the promulgation and the effective date of a new fee schedule, the new fee schedule is stored in a memory of a transmission means (chip card or cell of a GSM network) separated from the postage meter machine far before it takes effect. When the postage meter machine is turned on, the date of the calender module of the postage meter machine is employed or is combined with further input conditions in order to select the table that is loaded into the memory thereof when the postage meter machine is initialized. An updating of the previous table ensues by downloading the memory of the transmission means into of the memory of the postage meter machine.
U.S. Pat. No. 5,710,706 (corresponding to European Application 724 141) discloses a data input into a scale that is connected by an interface to a postage meter machine in order to update fee schedule table data with new data. The loading of the new data ensues by modem to the postage meter machine from a remote data center. The loading and updating ensue in immediate succession. When fee schedule table data are to be updated, a loading ensues and, given intermediate storage of fee schedule table data in the postage meter machine, a sector-by-sector deletion of the old postage table ensues in the non-volatile memory of the scale before the transmission of the new fee schedule table data from the intermediate memory of the postage meter machine to the scale and the write-in of the new fee schedule table data in the non-volatile memory of the scale. A number of tables can be stored in the scale, however, each table relates to a separate mail carrier that can be selected via a keyboard. The minimum validity of a fee schedule table allocated to a carrier identification number CIN is stored and interpreted by the postage meter machine in order, when needed, to form request data for loading new fee schedule table data, or for updating in the memory of the scale according to the CIN.
U.S. Pat. No. 5,448,641 discloses a postal fee system wherein a validity check is made in the terminal equipment at the user side. The postage fee schedule table is transmitted from the data center to the terminal equipment. A code belonging to the postage fee schedule is also transmitted from the data center to the terminal equipment. The latter generates a comparison code from information based on the received postage fee schedule table. On the basis of the comparison of the received code to the generated comparison code, the validity of the received postage fee schedule table can be checked in the terminal equipment. Although the terminal equipment can verify the communicated postage fee schedule table, the data center cannot check whether the current postage fee schedule table was in fact properly stored by the terminal equipment. In case of disagreement, the user could delay payment of the service or refuse it because no documentation exists about the storage of the postage fee schedule table that ensued in the terminal equipment. The manufacturer of the postage meter machine thus count not avoid an on site inspection of the machine.